Ever have a kid in class come up to you and say "I can't kick with this leg today because the dog stepped on my foot," or "He kicked me too hard" or some similar calamity? Sure you have. We all have. Usually every day.
What can we say? "Kick anyway!; Go sit down till you feel better; Kick with the other leg!", etc.
Now there's another option. Say - "You know, Johnny, that's what I admire about you. Most kids would have stayed home today if the dog stepped on their foot, but not you. You've got so much Warrior Spirit that you came anyway!" and slap a "Warrior Spirit" sticker onto their uniform.
"Wow!", your student will think, "Sensei says I've got 'Warrior Spirit!" And he or she will suck it up, stand a little taller, and carry on. Crisis resolved.